The UK Independence party, which has historically put in a lacklustre performance in local elections, has been averaging 13% of the vote in the seats it contested – five points higher than a year ago – making 2012 a record year for Nigel Farage's Eurosceptics.

Although it has so far failed to convert that share of the vote into a significant gain in seats, Ukip appears to have done more than enough to ruffle Tory feathers and put pressure on an already creaking coalition.

Gary Streeter, Conservative MP for Devon South West, lost no time in seizing on the defections as evidence of why David Cameron needs to reassert his party's traditional values. "We need to work out a strategy, certainly in the West Country, for dealing with the issue of traditional voters shuffling off and voting Ukip because they don't think our leadership is Conservative enough," he told the BBC.

"The Ukip vote is not just about Europe," he added. "It's also about a hard core of traditional Conservative voters saying, actually we don't like the kind of small-l liberal decisions this government is beginning to take. It offends our values and we're going to protest and vote Ukip."

Despite the solid vote share – the party's best in a local election not held on the same day as a European election – Ukip had returned only seven councillors with 99 of the 181 councils declared – a gain of one. In Thurrock, Rushmoor and North East Lincolnshire, the party gained seats on councils where the Conservatives lost them. But in Dudley, Sefton and Plymouth, it lost seats.

The mood in the Ukip hierarchy was nonetheless content. The deputy leader, Paul Nuttall, told BBC Radio 4's Today programme the party could be "quite happy" with the results. "We're certainly putting pressure on the other parties," he added.

Ukip, which has long campaigned for Britain to exit the EU, is keen to broaden its political base by calling for lower council tax and more grammar schools.

Farage is also keen to boost his party's traditionally poor showing at local polls, and the party fielded about 700 candidates for election on Thursday.

That was considerably more than the British National party's 131 candidates, a fact that was remarked on by Conservative co-chairman Lady Warsi.

Appearing to link Ukip's strong performance with the drop in BNP candidates, Warsi said: "Where Ukip is fielding candidates this time that the BNP did last time but they're not this time, I think that will have an impact." She added: "There are members of Ukip who are from all sorts of political parties, but it is an interesting mix there in terms of the number of candidates."

The comments sparked anger from Ukip spokesman Gawain Towler, who took to Twitter and referred to Warsi as a "bitch". In turn, he was criticised by some of his followers for the use of unparliamentary language and deleted the post with an apology. Nuttall also reacted to the comments, saying they were "disgraceful" and "a sign that the Conservatives are very scared of Ukip".